Oral mucositis can be a significant problem for cancer patients. It is typically associated with pain and increased risk of infection and can lead to impaired nutritional status and inadequate hydration.it can be seen in the patient population receiving high-dose head and neck radiation therapy (85%-100%). Topical dexpanthenol acts like a moisturizer, improving stratum corneum hydration, reducing transepidermal water loss and maintaining skin softness and elasticity. The stimulation of epithelization, granulation and mitigation of itching were the most prominent effects of formulations containing dexpanthenol. The investigators suppose that dexpanthenol mouth wash may improve oral mucositis.